Engineering Information

Miniature & Small ball bearings -7. Tolerance and precision grade

The bearings are classified into certain precision grades. The tolerances for each grade are found in JIS and ANSI/ABMA. Minebea's products are based on JIS B 1514-1,-3, ANSI/ABMA Std.12.2 and ANSI/ABMA Std.20 The symbols used in the specification are as follows.

Symbol

■Dimensions

d :Nominal Bore Diame

D :Nominal Outside Diameter

D1 :Outer ring flange outside diameter, basic

B :Nominal Inner Ring Width

C :Nominal Outer Ring Width

r :Chamfer Dimension of Inner Ring or Outer Ring

■Dimensional Differences

Δds :Dimensional difference of bore diameter

Δdmp:Dimensional difference of mean bore diameter in the plane

(Δdm):Dimensional difference of mean bore diameter

ΔDs :Dimensional difference of outside diameter

ΔDmp:Dimensional difference of mean outside diameter in the plane

(ΔDm):Dimensional difference of mean outside diameter

ΔBs :Dimensional difference of inner ring width

ΔCs :Dimensional difference of outer ring width

ΔD1s :Deviation of a single flange outside diameter

ΔC1s :Deviation of a single width of the outer ring flange

■Limit Values of Chamfer/Radius Dimension

rs :Chamfer dimension of inner ring or outer ring

rs min:Minimum dimension limit of inner ring and outer ring chamfer

rs max:Maximum dimension limit of inner ring and outer ring chamfer

■Inequality of Dimensions

VBs :Inequality of inner ring width

VCs :Inequality of outer ring width

VC1s:Inequality of flanged width

■Rotation Precision

Kia(Ki) :Radial runout of inner ring

Sia(Si) :Axial runout of inner ring

Sd(Sdi):Side runout of inner ring [runout of inner ring reference face with respect to the bore]

SD1 :[variation of outside surface generatrix inclination with respect to the outer ring flange back face]

Seal :Axial runout of outer ring flange back face

Remark ( ) is defined by ANSI/ABMA.

Reference [ ] is the expression used in previous JIS.

Attention : Above is only for radial ball bearing.

Referred from JIS B 1514-1

Tolerance of inner ring d ≦ 18mm

Unit : μm

Grade

Dimensional difference

Radial Runout

Perpendicularity

Axial runout

Dimensional difference of width

Inequality of width

Δdmp

Δds

Kia

Sd

Sia

ΔBs

VBs

Upper

Bottom

Upper

Bottom

MAX

MAX

MAX

Upper

Bottom

MAX

Grade 0

0

-8

-

-

10

-

-

0

- 40*1-120

12*1
15*220

Grade 6

0

-7

-

-

5*1
6*27

-

-

0

- 40*1-120

12*1
15*220

Grade 5

0

-5

-

-

4

7

7

0

- 40*2- 80

5

Grade 4

0

-4

0

-4

2.5

3

3

0

- 40*2- 80

2.5

Grade 2

0

-2.5

0

-2.5

1.5

1.5

1.5

0

- 40*2- 80

1.5

*1 the values apply only up to and including d = 2.5mm. *2 the values apply only up to and including d = 10mm.

Tolerances of outer ring D ≦ 30mm

Unit : μm

Grade

Dimensional difference

Radial runout

Perpendicularity

Axial runout

Dimensional difference of width

Inequality of width

ΔDmp

ΔDS

Kea

SD

Sea

ΔCs

VCs

Upper

Bottom

Upper

Bottom

MAX

MAX

MAX

Upper

Bottom

MAX

Grade 0

0

-8*1-9

-

-

15

-

-

0

- 40*2-120

12*2
15*320

Grade 6

0

-7*1-8

-

-

8*19

-

-

0

- 40*2-120

12*2
15*320

Grade 5

0

-5*1-6

-

-

5*16

8

8

0

- 40*3
- 80*4

5

Grade 4

0

-4*1-5

0

-4*1-5

3*14

4

4

0

- 40*3
- 80*4

2.5

Grade 2

0

-2.5*1-4

0

-2.5*1-4

1.5*12.5

1.5

1.5*12.5

0

- 40*3
- 80*4

1.5

*1 the values apply only up to and including D = 18mm.
*2 the values apply only up to and including d = 2.5mm.
*3 the values apply only up to and including d = 10mm.*4 the values apply only up to and including d = 18mm.

Flange outside diameter tolerance

Unit : μm

D1

Column 1

Column 2

(mm)

ΔD1s

Over

Incl.

Upper

Bottom

Upper

Bottom

10

+220

-36

0

-36

10

18

+270

-43

0

-43

18

30

+330

-52

0

-52

Remarks : When the flange outside diameter is used for location, column 2 shall apply.

Tolerances of flange width and tolerance of rotation precision related to flange

Unit : μm

D

Grade 0, Grade 6

Grade 5, Grade 4, Grade 2

Grade 0, Grade 6

Grade 5

Grade 4

Grade 2

(mm)

ΔC1s

VC1s

Over

Incl.

Upper

Bottom

Upper

Bottom

MAX

2.5*1

30

0

-40*2

-120

0

-40*3-80

12*2
15*320

5

2.5

1.5

Unit : μm

D

Grade 5

Grade 4

Grade 2

Grade 5

Grade 4

Grade 2

(mm)

SD1

Sea1

Over

Incl.

MAX

MAX

2.5*118

1830

88

44

1.51.5

1111

77

34

*1 D = 2.5mm is included in this dimension division.
*2 the values apply only up to and including d = 2.5mm.*3 the values apply only up to and including d = 10mm.

Referenced from ANSI/ABMA Std.12.2

Inner Ring tolerance d ≦ 18mm

Unit : μm

GradeABEC

Δdmp*

Δds

Ki

Sdi

Si

ΔBs

VBs

Upper

Bottom

Upper

Bottom

MAX

MAX

MAX

Upper

Bottom

MAX

3P

0

-5.1

+2.5

-7.6

5.1*17.6

-

-

0

-127

-

5P

0

-5.1

0

-5.1

3.8

7.6

7.6

0

-25.4

5.1

7P

0

-5.1

0

-5.1

2.5

2.5

2.5

0

-25.4

2.5

9P

0

-2.5

0

-2.5

1.3

1.3

1.3

0

-25.4

1.3

* Basically, grade 3P is provided as Δdm.*1 the values apply only up to and including d = 10mm.

Outer Ring tolerance D ≦ 30mm

Unit : μm

GradeABEC

ΔDmp*

ΔDs

Ke

Cs

Se

ΔCs

VCs

Open

shield/seal

Upper

Bottom

Upper

Bottom

Upper

Bottom

MAX

MAX

MAX

Upper

Bottom

MAX

3P

0

-7.6

+2.5

-10.2

+5.1

-12.7

10.2

-

-

0

-127

-

5P

0

-5.1

0

-5.1

+1

-6.1

5.1

7.6

7.6

0

-25.4

5.1

7P

0

-5.1

0

-5.1

+1

-6.1

3.8

3.8

5.1

0

-25.4

2.5

9P

0

-2.5*1-3.8

0

-2.5*1-3.8

-

-

1.3*12.5

1.3

1.3*12.5

0

-25.4

1.3

* Basically, grade 3P is provided as ΔDm.*1 the values apply only up to and including D = 18mm.

Referred from ANSI/ABMA Std.20

Inner Ring tolerance d ≦ 18mm

Unit : μm

GradeABEC

Δdmp

Kia

Sia

ΔBs

VBs

Upper

Bottom

MAX

MAX

Upper

Bottom

MAX

1

0

-8

10

15*120

00

- 40*1-120

12*1
15*220

*1 the values apply only over and including d = 0.6mm or up to and including d = 10mm. *2 the values apply only up to and including d = 10mm.

Outer Ring tolerance D ≦ 30mm

Unit : μm

GradeABEC

ΔDmp

Kea

Sea

ΔCs

VCs

Upper

Bottom

MAX

MAX

Upper

Bottom

MAX

1

0

-8*1-9

15

15*2
20*125

0

- 40*3-120

12*3
15*420

*1 the values apply only up to and including D = 18mm.
*2 the values apply only up to and including D = 6mm.
*3 the values apply only up to and including d = 2.5mm.*4 the values apply only up to and including d = 10mm.